Histamines are implicated in a number of medical conditions, including inflammation, asthma, allergy, atopic dermatitis, stroke, myocardial infection, migraine, chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, and psoriasis. Histamines regulate the intensity and duration of immune responses and are involved in cell-to-cell communication. Histamines are also involved in leukocyte migration and bronchovasoconstriction. As established by radioligand binding, physiological assays, and molecular cloning, different types of receptors for histamines exist. Furthermore, specific histamine receptor subtypes are involved in specific medical conditions such that drugs with subtype selectivity can be utilized to target individual medical conditions.
In view of the important role that histamines play in many physiological processes and medical conditions, there is a need for materials and methods useful for the identification of agonists and antagonists selective for the specific types of histamine receptors.